MEASUREMENT OF ACTIVITY OF TRANSAMINASES IN THE SERUM AS AN AID IN DIFFERENTIAL DIAGNOSIS OF JAUNDICE IN THE NEONATAL PERIOD

Abstract

Measurements of transaminases in the serum have proven of value in the diagnosis of hepatic diseases in adults. It therefore seemed of interest to apply these techniques to the newborn infant. To establish the normal range of the activity of these enzymes in the serum for the neonatal period, studies were made of glutamic pyruvic transaminase (GPT) in 63 normal newborn term infants for the first week of life. It was found that values for the activity of GPT up to 90 units must be considered physiologic for this early neonatal period. This compares to a physiologic neonatal range of activity up to 120 units for glutamic oxaloacetic transaminase (GOT), found in a previous investigation on these same infants. Thus the range of activity for these two enzymes in newborn infants is somewhat greater than that of adults in whom values up to 45 units for both enzymes are considered normal. In neonatal physiologic jaundice the degree of hyperbilirubinemia did not affect the activity of GPT, as was also the case, from previous studies, with respect to GOT. Serial determinations of the activity of GOT and GPT were also made in a small number of infants with jaundice due to pathologic conditions to determine the value of this test in the differential diagnosis of jaundice of unknown origin in the newborn infant. It was found that in hemolytic disease of the newborn, activity of these enzymes usually remains within the normal neonatal range. In very severe hemolysis, activity of GOT may be increased to about 300 to 400 units, temporarily, although activity of GPT remains within the normal neonatal range. In neonatal biliary obstruction there is a sustained increase of activity of transaminase in the serum which may reach values up to about 800 units for the duration of the obstruction, whether it be temporary, as in the "inspissated bile syndrome" or protracted, as in atresia of the bile ducts. It would appear that serial measurements of the transaminases in the serum may be of distinct diagnostic value in jaundice of unknown origin in the neonatal period, and it is suggested that this procedure be included in the investigation of a clinical problem involving this syndrome.